Should You Use Synthetic Fibres?

While this might sound a little obvious to some, not everyone realises the difference between synthetic and natural fibres – or they may simply not realise which fibres are man-made and which are natural.

That being said, natural fibres can sometimes be almost as bad ecologically as synthetic ones, so which should you choose? Ultimately, the decision should come down to what’s best for your project. No one should be made to make a project out of a fibre wholly unsuited for that purpose through fear of other people’s judgement. There’s also the murkiness which surrounds artificial fibres and whether they’re natural or not – but we’ll deal with them in another post.

The point of this series of posts – as well as supporting your fabric and fibre choices in your crochet, sewing and knitting efforts – is to give you facts about different fibre types so you can make an informed decision on what’s best to use for your project. Let’s start with synthetic materials which are commonly available.

pile of folded textiles made from synthetic fibres
Materials made from synthetic fibres include felt, satin dress lining, microfibre cloth, interfacing and polar fleece

6 examples of synthetic fibres

Polyester

Polyester is a strong, durable and versatile fibre which is commonly used in textiles and dressmaking. It can be made from natural fibres by using chemicals found in the waxy surface of various plant leaves, though it is typically made from plastic. Most thread, interfacing, wadding, batting and stuffing is made from polyester, plus it is a popular choice for clothes and material. Polyester is commonly used in making waterproof items, such as jackets and tents, as it can be easily coated and strengthened. For all its strengths, it also has many weaknesses – it’s not very good at absorbing moisture and so it can get sticky and uncomfortable to wear quite easily, for one. It’s not biodegradable, it sheds micro fibres into water supplies when washed and it is also very heat sensitive, meaning it can melt and degrade at high temperatures. It’s becoming easier to get hold of recycled polyester as thread and fabric, though this still has the same issues as virgin polyester.

Nylon

The wonder fabric of the 1940s, there were riots after WWII when people couldn’t get hold of nylon stockings! While polyester is similar to cotton in feel, use and weaving, nylon is silky and stretchy when woven in a particular way, making it ideal for hosiery, lingerie and even parachute silks. It’s estimated to have the same carbon footprint as wool and with a longer lifespan if looked after properly, but it also has the same issues as polyester. If wearing a vintage product or using vintage fabric made from “pure” nylon from the 1940s and 50s, be aware that in some conditions it can degrade back to its original components. It’s also not all that strong and can easily get runs or tears, particularly in tights and stockings.

nylon is a popular synthetic fibre
Inspection of nylon stockings at a factory in Malmö, Sweden. Photograph by Erik Liljeroth in 1954

Acrylic

Acrylic is probably the one fibre I would suggest avoiding at all costs. While it is soft, warm and lightweight, it is responsible for shedding the most microfibres when washed of any synthetic material – according to a study by Plymouth University, it releases nearly 730,000 microfibres per wash into the water! These microfibres don’t just end up in our environment, but they’re so small they’re even in our drinking water supplies. Many cheap yarns are made from acrylic and it is even found as a blend with other fibres, including wool – so those of you who knit and crochet, it’s worth double checking yarn for acrylic content before you buy it!

Spandex

Spandex is also known as lycra and elastane, spandex is an incredibly stretchy material. It’s commonly used for sports clothing, such as swimwear, shorts and cycling clothes and is more often than not blended with cotton or polyester – how many of you have t-shirts which are a blend of cotton and elastane? I know I have some. In fact, spandex is in a lot of commercially produced clothing – particularly women’s clothing (think bras, underwear, tights, leggings – anything involving some stretch, body shaping or body contouring). In addition to releasing hundreds of thousands of microfibres, spandex is especially difficult to recycle and so most items containing spandex are simply discarded and become environmental pollution.

Polyurethane

Polyurethane is commonly known as PU, polyurethane is typically found in foams (including upholstery and bedding foam) and also footwear. It’s the base material for spandex and can also be made into a film which is applied to fabrics to make them waterproof – cheap “oilcloth” is typically PU coated, such as you would see on table cloths in children’s nurseries or greasy spoon diners. It’s also found in nappies, shower curtains and waterproof gear like jackets. Being a plastic polymer, it doesn’t biodegrade and like spandex it’s very difficult to recycle, so it ends up being discarded.

Neoprene

Neoprene is a synthetic rubber material most commonly used in wetsuits, but also used in footwear, laptop and phone cases, halloween masks and a multitude of other products. It’s not clear what the environmental impact of this product is, but it’s favoured commercially for being durable, strong, insulating and waterproof. Some people suffer from contact dermatitis and allergies to neoprene, so this is something to be aware of if using or gifting products containing it.

Wetsuits are necessary for keeping you safe in some watersports, but neoprene can be problematic for some.

Could synthetic fabrics be more suitable for your project?

There are times where using synthetic fibres is more appropriate than using natural fibres. For example, polyester thread is generally considered better to use when sewing leather than natural fibres, as the tannins used in leather production can degrade natural fibres very quickly.

The decision to use synthetic fabrics is one which should be carefully considered for your project, just as you would the colour or pattern of the fabric. If you need a highly durable, waterproof material then it still may be your best choice to use a synthetic material. Wherever possible in these situations though, my recommendation would be to choose a material made from recycled plastics, as this helps to reduce plastic pollution without compromising the quality of the fibre. It’s becoming easier to get hold of what’s known as rPET (recycled Poly Ethylene Terephthalate) in thread and fabric form and much of this is created from recycling single use products such as plastic bottles. If you’re lucky, you might even find some rPET made from plastic recovered from the ocean.

Be aware of materials including taffeta, chiffon, satin and organza. These materials can be made from either synthetic or natural fibres, but unless it specifically states that these fabrics are made from silk or silk/cotton blends, it’s likely that these will be cheap synthetic fibres. They’re also notoriously difficult to work with and probably aren’t the best choice if you’re a beginner sewist.

Most zipper tapes are made of synthetic fibres
Synthetic materials can be hard to avoid in cases such as zipper tape

There are also some uses of synthetic fibres where you may not even realise you’re using them. Zips are a prime example – even if you use zips with metal teeth, it’s almost certain that the tape of the zip is made from polyester or nylon. Zips made with cotton or lyocell tape do exist, but they’re difficult to get hold of and there’s some concern that it’s just a bit a greenwashing and the technology required to produce them en masse isn’t really there. Stuffing, interfacing, wadding, batting, etc are all commonly made from polyester and most of the time it’s not even labelled what the fibre is. Most buttons and fastenings are plastic based too, unless you search for alternatives.

You might be thinking “oh well, if it’s difficult to find things that aren’t plastic based, what’s the point in looking for them?” I can appreciate that sentiment – we don’t always have the time or the energy to look for alternatives to plastic, and sometimes it’s more expensive to get products made from natural materials. But if you look even casually, they are there, they just don’t tend to be pushed or marketed as heavily as plastic based products.

Frequently asked questions about synthetic fibres

“Where can I find details about the composition of a fabric?”

Most fabric suppliers will have a section on their website detailing the composition of the fibres – for example, this could read “100% polyester”, “95% cotton, 5% elastane” or something similar. If you can’t find these details, ask the seller. Rolls of fabric always come from the manufacturer with details of the composition, so the seller will be able to tell you what fibres it’s made from. This might be slightly more difficult for remnant and off cut pieces, particularly if purchasing from a market stall, but they should still have the details somewhere.

“How do I know if a fabric/thread is made from recycled material or not?”

It comes down to having a bit of trust in your supplier; if they state on their site or in their shop that the fabric is composed of recycled materials or has a certain amount of recycled materials in it, then it should be made of the stated materials. If it’s from a well known fabric manufacturer, you might be able to double check on their website, or even ask them directly over social media. Thread is a little bit easier, as it normally states on the spool what it is, plus there’s a couple of brands you can look out for. Gütermann have a range of Sew All rPET and Top Stitch rPET threads which comes on spools with a green bottom to them, plus Crafil have Denimfil® Eco.

“What options are there for non-plastic notions, like buttons?”

There are apparently some zippers which are made using rPET for the zipper tape, though you’d have to confirm this is the case with the supplier, as they’ll know which types of zipper they’ve purchased. Sadly it seems that no one makes zipper teeth from recycled materials yet though – hopefully this will happen soon as it makes sense to used recycled brass for metal zipper teeth. In terms of buttons, you can of course get buttons made from wood, shell, coconut and horn, though you wouldn’t want to put these in a washing machine! Metal buttons are a good option for items like shirts, where you’re likely to need something really durable, but there’s also corozo and codelite. Corozo is also known as vegetable ivory; it’s incredibly tough and scratch resistant while also being super sustainably sourced (the nuts can only be collected and used once they’ve fallen from the tree). Codelite is made from a protein found in milk called casein and it’s produced from milk that would otherwise be wasted. It’s actually the material that many button manufacturers used up until the 1970s when polyester took over, so there’s a reasonable chance that vintage buttons from before then are made of codelite.

“Should I throw out the synthetic materials I have and start again with more sustainable options?”

No! There’s no need to just throw something out, even if it’s not made from a particularly sustainable material. If you decide you really don’t want to continue using something (for example, if you have half a spool of polyester thread), it’s far better to give it to someone who will use it than to just throw it in the bin. Fabric swaps can also be a great way to give remnants and offcuts of fabric a new lease of life if you no longer want to use it, as there’ll always be someone else who is interested in it. Ultimately, the most sustainable thing you can do as you start to look for and buy more sustainable materials is simply to use what you already have. If you know that it’s a material which is bad for shedding microfibres, invest in a Guppyfriend washing bag which will catch most (if not all) of the microfibres if and when you need to wash the item and (as we should be doing with all of our clothes really) make sure you get the most life out of your makes by caring for them and repairing them when needed.